Device for regulating the air supply to furnaces of steam boilers



S. DEUTSCH DEVICE FOR REGULATING THE AIR SUPPLY `TO FURNAcEs oF TEAMBILERS Filed June 23 1920 3 Sheets-She'et l ,em/1, mw www@ 1,480,673Jan" 15 1924.' s. DEUTSCH l DEVICE FOR REGULATING THE AIR'SUPPLY ,TOFURNACES OF STEAM BOILERS Jan. 15 1924. 1,480,657?,

s. br-:UTscH DEVICE FOR REGULATING THE AIR SUPPLY TO FURNACES OF STEAMBOILERS Filed Jun@ 2s. 1920 :s sheets-sheet 5 Patented Jan. 15, 1924.

SIZES-FRIED DEUTSCH,

OFFICE. f

OF VIENNA, AUSTRIA.

L DEVICE FOR REGULATING THE AIR SUPPLYv TO FURNACES 0F`S'LKLTAIYEILOIII'JIERS. r i

Application filed June 2a,

To all whom t may. concern: y Be it known that I, SIEGFRIED DEUTSCH,mech. engineer, citizen of the Republic of Austria, residing at Vienna,Lower Austria, Austria, have invented certain new and usefulImprovements in Devices for Regulating the Air Supply to Furnaces ofSteam Boilers, of which the following is a specification. This inventionrelates to devices for regulating the air` supply to furnaces of steamboilers'y the object being to provide an improved device for maintaininga predetermined steam pressure in the boiler.

In the known regulating devices of this kind, a member is provided whichis moved to different positionsby and in conformity with the variationsof the pressure of the steam in the boiler and varying thereby thecross-section of the air passageleading to the furnace of the steamboiler; these devices have the drawback that the raise and fall of thesteam pressure in the boiler are proportionally transmitted to theregulating member, that is to say, a gradually increasing of the boilerpressure causes a gradual movement of the regulating member for closingthe air passage and vlce versa. Therefore a slow or lingering openingand closing ofthe airr supply passage is produced, which is practicallynot very suitable for maintaining a fixed, predetermined pressure in theboiler.L

Bymeans of the present invention the following results are obtained: 1/the air supply passage to the furnace remains totally open until thedesired steam pressure in the boiler is attained, 2/ that the air supplyis rapidly stopped, when the steam pressure in the boiler rises abovethe desired pressure and 3/ that the air supply passage is rapidly,reopened when the pressure falls below the desired value, so that thesteam pressure may be maintained substantially constant.

The. new device is constructed in such a manner that it is adapted to beused also for maintaining various predetermined pressures if adjustedaccordingly.

The accompanying drawing illustrates one mode of application of thedevice according to the invention and the arrangement of its essentialkconstituent parts, Figure 1 is a vertical section view of the lowerpart of the apparatus, and Figure 2 is a vertical section view of theupper part of the apparatus above section AA of Figure 1. Fig. 3 is a`1920. serai No; 391,249.'

diagrammatical view illustrating the complete apparatus in a simplifiedmanner;

The regulator proper, consists of la con tainer 1 for liquid in which ismounted a cap 2, the lower edge of which is at an angle to thehorizontal. Around a'circular opening in the'bottom Aof the container 1is a tubular piece 3 reaching into the interior of the cap 2 and beingprovided with lateral openings t. To the lower edge of the tubular piece`3 is connected a tube 5 leading to the furnace of the boiler. The`upper opening of the container 1 may be provided with a rotatable slidevalve 6 tor roughly adjusting the entrance of air. The air enters fromabove into the container 1, flows down around the exterior of the cap 2and beneath the lower edge into the interior ofthe cap, from therethrough the openings 4 into the tubular 4piece 3 and through the tube 5to the furnace. In case ofthe liquid, preferably water, standing only sohigh in the container l that the edge of the cap `2 is completely free,the cross-sectionof the air passage is a maximum and the maximumquantity of airl may tlowto the furnace.` Thej higher the liquid rises,the smaller becomes the cross-section of the air passagey and in caseofthe cap edge immersing totally into the liquid, the air canv no longerenter into the interior of the bell and the flow of air is interrupted;L

. The container 1 of the regulator communicates'by means of a pipe 7with a reserve vessel 8 in which normally the level of the liquid is atthe same height as itis in the container, viz'at such a height that thecap is out of contact with `the water.` lf the pressure in thereservevessel 8 increases, the liquid is partly driven out and the levellowers, whereas the liquid in the regulator container thereby rises, sothat it is only necessary to make the pressure in the'reserve vessel 8`depend on the pressure in the boiler for. having theair supply to thefurnace controlled by the steam pressure in the boiler. With this objectin view the air space of the reserve vessel 8 is connected by means of a-pipe to a vessel 9 having a downwardly extending tube 10, which is openat its lower end and is slidably yinserted in a tube 11,

arrangement being made that the tube 1() fits tightly in the tube 11..This latter has a branch 12 leading to the water filled part of thesteam boiler or to a container, the

'somewhat larger this tube produced by trates from below intofthe tube10. The

communication between the air space of the reserve vessel` with (the airspace of the vesselllhis eiected by means of therefollowing` device :,Byakpipe 13 eitendingupwards from ,the bottom o the;` reserve vesvendsFand E,connected at `its lower end Awith a `.pipe14a `fitting 15 andavertical pipe 16 ,which passes :through thel vessel 9., and has an upperopen end, the up'per'part ofthis pipeitlG being surrounded bya tube "ofa diameter which yis closed at its ,upperend and s mounted on theL coverYofthe vessel 18. this way,.the yairspace .of the vesselq9 communicateswiththe tube 16, ,by interstices left between this n tube'` 16 and Iitssurrounding `ltube 17, this air passage being indicated by arrows.

.When thei furnace is'y kfired, the Ipressure in A,the boilerV increasesgradually, thel water in pipe 10 rises without lpractically increasingthe ,air pressurein lthe vessel 9`on account oithis pipe beingcomparatively small 4and .therefore only a small Vquantity of Yairis-,displaced bythe rise of thewater. Consequentlythe liquid in theAreserve vessel 8 isnot exposed to a substantially v.increased pressureandutheregulator is therefore not lappreciablyavactuated. The airsupplypas- `sagesoit` this regulator remain entirely open sotliat ytheintensity of ftlie,iurnace firing is maintained. The rise of lthe'columnof water in the tube 10 in cnse'quencek ofthe increase oit 4.thepressure in the boilergis ind dependent of the cross-section ofthis'tube,

e.; Tol every degree of pressure corresponds .fa.certainheightfofthecolumn of water, no matter how large be thecross-section .of theyy.tube'communicating' with the boiler. Howeverthe increase of thevolume of water in the rise of the column of. water, vwhen the lpressureI increases, :de-

.pen'ds upon the cross-section of the tube. It

it is assumed that the boiler pressure begins toliiicrease at a uniformrate when the level .ot the liquid in tube 10 is below the bottom Y oivessel 9, the height of the levelo'f the .liquidin `tube 1,0 Vwillincrease in proporvtionto the increase in boiler pressure. It

f, .the frictio'nof the,l pipe connectionsbe neg- ,lected, this relationbetween the height of thelevel of the liquid and the boiler pres- VVsurereniainsbonstant, as the level of the liquid rises-in tube 1Q and in thevessel 9.

a The increase in they height of theV level o the liquidisalwaysproportional to the increase in'boilei` pressure, regardless ofthe The tube 11u is'of V:the liei'ghtwofthelevel oi the liquid in thecross-section Y of the passage in which the liquid is rising. i 'Adeiiitey increaselor decrease in boiler pressure will produce a cor'-res'poiidingly deiinite increase or decrease in regulating device, thechange in the height Vofthe level ot the'liquid being proportional tothe change inboiler pressure, regardless ot vwhetherthelevel of theliquid is below the bottom of vessel 9 or above this point. It therefore`true that a certain change in the levelot vthe liquidkv whenthis 'levelremains below the bottom of yvessel 9` will produce a very smalldisplacenient'otfluid from the top of vessel 9, whilethe 'saine changelinthe level of the liquid, v'when this level ,is above the bottom oitthevessel 9, will produce aconsiderable'displacement oi the fluid in thetop of 'vessel 9.9111' lother words, a given change inboilerpressurewill producev a sliglitdisplacement otthe yfluid in the topv ofvessel 9, when the level oi' 'the liquid ilowingiin tube 10 is belowithel bottom of vessel 9; and a considerable displacement of the fluidin the top otvessel 9when the leveloi:p the liquid is abovethe'bottom ofvessel 9. "For a given rate of change in boiler pressure, the rateofilowthe liquid in tube 10 is much greater of course when the level ci thisliquid is above thebottom oi vessel 9than when the level oftliis' liquidis below the bottom of vessel 9. This sudden and large increase of'volume causes a sudden increase of the air pressure iii the vessel 9 onaccount oifthe sudden decrease of yvolume of the air space iiithisvessel. 'lhis increased air pressure rapidly forces the liquid in'the reserve-vessel 8f through the connections 17, 16, 15, 14, 13, thuscausing Ia Arapid rise o the liquidv iii the contaiiier 1 of theregulator and simultaneously a rapid closing of the air passageVhen 'theboiler pressure decreases, the decrease ot volume will be'co'nsiderableand cause a rapid opening o'fytheui passage' as long as the water iswithinthe vessel 9.: 'n lVh'en the water sinks below the vessel 9,iifurther noticeable change in the regulator will 'take place, becausethe decrease of volume becomes less on account of Athe smallvcrosssection of tube 10. 1n this way ajpredetermined pressure in theboiler .may be pre ci'sely maintained.

(llo bev more specific, the oiliera'tion of the device is as follows 1')assume that the 4apparatus is adjus'tedto yregulate toi' agivenpressure. li pressure in the boiler is below this value the level ot theliquid in `themtubes lOand 11"'will besoiiiewhat'below `the' bottoni ofthe vessel 9, andthe cross sectionl of theair passage in the regulatorproper` will beM a maximum. Villienthepres sure has increased to thevOi'veii value' Vthe level ot the liquid iny tube10 willbe even with thebottom of the vessel 9, and the air" passage will still be wide open. Asthe pressure increases beyond the given value, the height of the liquidwill increase correspondingly. This increase in height causes a largevolume of the liquid to enter the vessel 9, due to its large crosssection. This sudden change forces the fluid from the upper part of thevessel 9 through the communicating connections 17, 16, 15, 14 and 13into the container 8. This causes an increase in pressure in thiscontainer 8, thus forcing the liquid therein through the pipe 7 into theregulator; and as the liquid rises in the regulator, the air passage israpidly closed. This shutting otl' of the air supply lessens the rate ofcombustion, and the pressure in the boiler decreases accordingly untilthe given value is reached.

In order to adapt the device for maing taining different degrees ofpressure in the boiler, the vessel 9 may be adjusted to difilerentheights. For this purpose the vessel 9 is guided along the pipe 16 whichpasses through it and is surrounded by a chamber 18 having at its upperend a tubular extension 19 closed at the top. The pipe 10 is slidablymounted in the tube 1l, and passes through a packing 20 in the bottom orchamber 18.` When the vessel 9 is adjusted to a higher level, thepressure in the boiler must become correspondingly higher before thewater will enter the vessel 9. When the vessel provided with anindicator movable along a vertical scale ixed on the outward side otchamber 18 and indicating the boiler pressure tobe maintained, it ispossible to so adjust the height of the vessel 9 that the regulatingdevice will regulate for any desired boiler pressure.

In order to obviate the loss of the liquid by evaporation a film of oil21 may be put on the surtace ot the liquid in the regulator vessel l.

It is understood that I do not limit myself to the described details ofconstruction which might be modified in various ways without departingfrom the spirit oi: the present invention. l

IV hat I do claim as my invention and desire to secure by Letters atentis,

l. In a device of the character described having an air passage, thecombination of a regulator proper -for varying the crosssection of theair passage, and fluid pressure means for actuating the regulatorproper, said means comprising a reserve vessel for holding a liquid, apipe connection between the lower part of said reserve vessel and saidregulator proper7 a vessel of relatively large cross-section, a pipeconnection between the upper part ofsaid reserve vessel and the upperpart of said vessel ot large cross-section, a pipe connection ofrela-tively small cross-section between the lower part of said vessel oflarge cross-section, and the boiler, said pipe connection being normallylilled with a liquid upto the bottom of said vessel of largecross-section.

2. In a device of the character described having an air passage, thecombination of a regulator proper for varying the crosssection of theair passage, and Huid pressure means for actuating the regulator proper,said means comprising a reserve vessel for holding a liquid, a pipeconnection between the lower part of said reserve vessel and saidregulator proper, a vessel of relatively large cross-section, a piperconnection between the upper part or said reverse vessel and the upperpart of said vessel of large cross-section, a pipe connection ofrelatively small cross-section between the lower part of said vessel oflarge cross-section and the boiler, said pipe connection being normallyfilled with a liquid up to the bottom of said vessel of largecross-section, and said vessel of large cross-section being adjustableto any desired height.

3. In a device of the character described having an air passage, thecombination of a regulator proper for Varying the crosssection of theair passage, and iuid pressurek means for actuating the regulatorproper, said means comprising a reserve vessel or holding a liquid, apipe connection between the lower part of said reserve vessel and saidregulator proper, a vessel of relatively large cross-section, a pipeconnection between the upper part of said reserve vessel and the upperpart of Said vessel of large cross-section, a pipe connection ofrelatively small cross-section between the lower part of said vessel oflarge cross-section and the boiler, said pipe connection being normallylilled with a liquid up to the bottom oit' said vessel of largecross-section, and said pipe connection between the lower part ot' saidvessel of large cross-section and the boiler being adapted to permitadjustment of said vessel at any desired height.

4. In a device of the character described, a regulator proper forcontrolling the supply of air to the furnace, a pipe of relatively smallcross-section communicating with the boiler, a vessel of relativelylarge cross-section communicating with said pipe, and a reserve vesselforpholding a liquid, communicating with said vessel of largecross-section and with said regulator proper, said lvessels and pipebeing arranged so that changes in boiler pressure near a predeterminedvalue will produce a rapid flow of the liquid between the reserve vesseland regulator proper, while corresponding changes in boiler 'pressureconsiderably below the predetermined value will produce only slight flowof the liquid.

In testimony whereof I affix my sign'ature.`

ING. siEGFRiED DEUTSCH?

